A plasma display panel (hereinafter referred to as a PDP) is a display device with a large screen, a low-profile, a lightweight body, and excellent visibility. A difference in discharging divides PDPs into two types of the alternative current (AC) type and the direct current (DC) type. In terms of the structure of electrodes, the PDPs fall into the 3-electrode surface discharge type and the opposing discharge type. In recent years, the dominating PDP is the AC type 3-electrode surface discharge PDP by virtue of having higher resolution and easier fabrication.
Generally, such a PDP contains a front plate and a back plate oppositely disposed with each other, and a plurality of discharge cells therebetween. The front plate consists of a front glass substrate, scan electrodes and sustain electrodes which form display electrodes and are disposed on the front glass substrate. A dielectric layer and a protecting layer are formed to cover the display electrodes. On the other hand, the back plate consists of a back glass substrate and the address electrodes are formed on the back glass substrate so as to be orthogonal to the display electrodes. The address electrodes are covered with a dielectric layer, and over which, barrier ribs are formed in parallel with the address electrodes. Furthermore, phosphor layers are formed between the barrier ribs and on the surface of the dielectric layer. Discharge cells are formed at each intersection of the display electrodes and the address electrodes.
In the manufacturing process of PDPs, scan electrodes and sustain electrodes and other necessary components are disposed on a front glass substrate as a front plate; similarly, address electrodes and other necessary components are disposed on a back glass substrate as a back plate. The front and back plates are oppositely positioned so that the scan electrodes and the sustain electrodes are orthogonal to the address electrodes, and then hermetically sealed on the peripheries. After that, a discharge space between the two plates is filled with discharge gas. A PDP is thus fabricated.
In driving a PDP, application of voltage for providing the entire PDP with uniform lighting (hereinafter, operating voltage) is required. In such a PDP that has just finished the assembly process, generally, the operating voltage is too high, and the discharge itself is in an unstable condition. The PDP therefore undergoes aging in the manufacturing process to lower the operating voltage and obtain consistent and stable discharge characteristics of each discharge cell.
For aging PDPs, a method—in which anti-phased rectangular waves are applied to the scan electrodes and the sustain electrodes for a long period of time—has conventionally been employed. To shorten the time for aging, some methods have been suggested. For example, Japanese Patent Unexamined Publication No. 2002-231141 introduces a method in which discharge is generated between the scan electrodes and the address electrodes in addition to the discharge between the scan electrodes and the sustain electrodes. Specifically, pulse voltage having different polarity is applied to the scan electrodes and the sustain electrodes, and at the same time, pulse voltage having a polarity the same as that applied to the sustain electrodes is applied to the address electrodes.
Even employing the methods above, the aging time still requires about 10 hours before completion of aging, that is, before obtaining preferably low operation voltage and stabilized discharging. The long aging time inevitably increases power consumption in the aging process, which has been a leading cause of increasing the running cost of manufacturing PDPs. Besides, the time-consuming aging process has caused problems: the factory space for keeping the PDPs for the aging process, and environmental conditions, such as air-conditioning, for properly maintaining the PDPs through the manufacturing process. From now on, further increase in manufacturing volumes and screen-sizes of the PDP apparently swells up the problems above and invites serious conditions.